The influence of operational parameters and feed preparation in a convective batch ribbon powder mixer

The results indicated that the homogeneity of the mixtures was influenced by the blender rotation speed and mixing time. Better mixing can be obtained with higher rotation speeds and longer mixing time. It was also observed that preblending and smaller feed particle size achieved the required homogeneity in a shorter period of time at a lower rotational speed. These results illustrate that using binders with a smaller particle size and a preblending technique improves the mixing process in a convective batch ribbon powder mixer. However, prolonged periods of high-speed mixing will lead to mixture segregation

Effect of grater position on the size of grated sago (Metroxylon spp.)

The natural arrangement of sago palm’s fiber orientation is parallel to the vertical axis of the trunk. Extraction of the sago starch requires breaking of the trunk into fine sizes. The sago size is affected by the grater position which affects the of starch recovery. This study was conducted to evaluate grating efficiency through sago size produced at the different direction of grating (0° and 90° to roller teeth rotation). Sago palm trunks without outer layer were cut into square blocks of 100 mm3. Each trunk block was placed on roller grater platform at a different position where the cutting spike was parallel to the vertical axis of sago trunk fiber orientation (grating at 0° direction) and perpendicular (grating at 90° direction). 100 g of dry grated sago was sifted to determine the size distribution with different sieve sizes i.e. 2.80 mm, 2.00 mm, 1.00 mm, 0.85 mm and 0.425 mm. A total weight of 1 kg of grated sago was mixed with water and squeezed to be extracted. The starch recovery produced by the grating process at 0° directions was 10.30% higher than 90 0 directions. The present study showed that the direction of grating at 0° was able to produce finer grated sago with maximum starch recovery

Study of machines performance in producing different sizes of grated sago

Sago starch is a product from sago palm. In order to extract the sago starch, certain process is needed to break the bonding of the pith either mechanically or manually by grating the pith into small sizes. Water is widely used as a solvent medium in the extraction process of sago starch. The more refined that grated sago, the more sago starch can be dissolved from the grated sago. Different machines were used to produce grated sago for machine capability test. The machines are handheld chainsaw, coconut husk decorticator, commercial coconut grater and in-house roller grating prototype. Sago palm trunk was cut into three parts with length of 50 cm long each. The outer layer of each sago palm trunks was peeled off and split into 8 pieces. All sago trunks were grated using four different machines as stated above. Each 100 gram of the grated sago trunk produced by each machine were sifted according to the grading size of 2.80 mm, 2.00 mm, 1.00 mm, 0.85 mm and 0.425 mm. The weights of sago starch from the sieving process were recorded according to their respected grading size. Based on results of the sieve experiments, the most finest grated sago trunk was produced from the handheld chainsaw with a weight percentage ratio of 13.028% (X < 0.3 mm), 10.682% (0.3 ≤ X < 0.425 mm), 28.361% (0.425 ≤ X <0.85 mm), 28.821% (0.85 ≤ X <1.0 mm), 4.728% (1.0 ≤ X <2.0 mm), 7.877% (2.0 ≤ X <2.8 mm), and 4.868% (X ≥2.8 mm) where X value refer to sieve mesh size